Physiological And Proteomics Analysis Of Plant Under Cd Stress And The Effects Of Rare-earth

Heavy metal pollution becomes more and more serious with the highly developing industry. Not only heavy metal pollution destroy the ecological balance and make worse environment, but also it can cause more damage through accumulation in food chain. As we all know, plant plays an important role in our daily life, it is of great importance to investigate the heavy metal pollution resistant mechanism of plant. Expression of a variety of genes is induced by these stresses in various plants. The protein products of stress-induced genes often accumulate in response to unfavorable conditions. The functions of these proteins and mechanisms that regulate their expression are currently a central topic of research in stress physiology.Biological analysis of epidermis, measurements of physiological and biochemical indexes, two dimensional electrophoresis and MALDI-TOF MS analysis are used in this research to study the effects of Cd in plant stomatal movements, physiological and biochemical changes, and differential expression of proteins, and the protection of La under stress Oryza sativa L and Arabidopsis thaliana. The results show as blew:(1) Cd inhibits stomatal openings of WT Arabidopsis thaliana in a dose dependence manner, the higher concentration Cd is, the smaller opening the stomatal shows. However, CASas of Arabidopsis thaliana stomatal movements are not affected by Cd. The results indicate that Cd may regulate the stomatal movements of CASas Arabidopsis thaliana through receptor. The signal transduction of heavy metal suppression may function through CASas and a series of cellular reaction to cause the closure of stomata.(2) Rice seedlings show slower growth, yellow leaves, chlorophyll decreasing, inhibition of POD, CAT activity, APX activity increasing, carbohydrate and praline significantly increasing under Cd2+ stress. However, La treatment can relieve the loss of chlorophyll, improve the activity of CAT, root growth, decrease APX activity and regulate the contents of carbohydrate and praline.(3) This study creates a proteomic expression map of rice under Cd and La treatment and uses MALDI-TOF MS and database index to analyze 51 target proteins. Totally, there are 43 proteins can be identified, the success rate is 72%. Among these proteins, 7 are up-regulated, 5 are down-regulated and 3 are new synthesis proteins under Cd treatment; 4 are up-regulated, 11 are down-regulated and 1 is new synthesis protein under La treatment. The results show that most of the up-regulated proteins under Cd treatment and most of the down-regulated proteins under La treatment are various metabolic enzymes, which indicates that La might protect plant through the regulation of enzyme activity. Under Cd+La treatment, 3 proteins are up-regulated, 3 are down-regulated and 2 are new synthesis proteins. GDSL-like Lipase is up-regulated under Cd treatment and down-regulated under La treatment, which indicate that this specific protein directly related to Cd stress and La repair mechanism.